Ray Kelly, the NYC Police Commissioner, seems to believe that "Stop and Frisk" has been responsible for the decrease in murders during Mayor Bloomberg's term. He says so himself in an op-ed in the Wall Street Journal. As usual, when someone starts throwing around statistics, I think it is a load of horse hockey.
To begin it rests on the premise that "In the 11 years before Mayor Michael Bloomberg took office, there were 13,212 murders in New York City. During the 11 years of his administration, there have been 5,849. That's 7,383 lives saved..." So lets start without even looking at any statistics.
The 11 years before Mayor Bloomberg took over (1991-2001), included the years 1991-1994 which is when the US saw some of the highest violent crime rates in all categories. NYC also had rates that were usually reserved for nearly lawless third world countries. But Guiliani cleaned that all up, right? At least that is what he took credit for.
Using the FBI Uniform Crime Report tool, I did a quick analysis of what happened in NYC and the US during two periods 1992-2001 and 2002-2011. Ten years each (because the FBI doesn't have the final 2012 numbers online yet). If "Stop and Frisk" has been effective, then not only should it show an improvement from the earlier years, but it should also show an improvement compared to the rest of the country which doesn't have "Stop and Frisk."
I compared three geographic areas: New York City, New York State minus New York City, and the United States minus New York City. Comparing the two 10 year periods, Bloomberg had only 49% of the murders as the previous. New York State had 92%. The US had 84%. So, initially it is looking like Bloomberg may be on to something with "Stop and Frisk."
But those are total numbers of murders, and as already mentioned it was comparing a time when we had the highest murder rates of the last century to a time when we had some of the lowest murder rates of the last century, not exactly a fair comparison. So lets compare rates instead. The population of New York City has grown by about 10% over the last 20 years. The State of NY (minus NYC) has grown about 5%. While the US has grown by more than 20%.
Between 1992 and 2001 the murder rate in NYC dropped by 67%. In New York State, it fell only 41%, and in the US it fell 37%. So, if Guiliani wants to tout his crime fighting prowess, he definitely has a leg to stand on (although I would dispute this as well).
How about Bloomberg. From the start of his reign, 2002 through 2011, the murder rate fell 14%, with "Stop and Frisk." In the rest of New York State, without "Stop and Frisk" the rate fell 21%, and the US it fell 17%. Both of those more than Bloomberg's fiefdom. But New York City is a big city, right?
Right, so I used the UCR tool to compare with other Metropolitan areas over 1,000,000. There are 10 in the US. Only two had a change in murder rate from 2002-2010 that was worse than New York City. Los Angeles cut their murder rate by 55% in that period. More impressive is San Diego which had a murder rate already half of New York's and they cut their's by more than 40%. So, seven out of nine large cities had larger decreases in the murder rate than New York City, without using "Stop and Frisk."
So, is "Stop and Frisk" effective? I don't know, but the murder statistics that Ray Kelly uses certainly don't show that they are. New York's decrease in murder rate has been rather anemic. Even if I look at the overall violent crime rate, two cities are less, three are the same, and three are more than New York. So New York appears to have had a typical decrease in crime for the time period.
So, the question that should be asked is, if "Stop and Frisk" doesn't show a significant decrease in violent crime and it has the potential to violate the rights of citizens, then why do it? There doesn't appear to be an upside (decreased crime) but there is all sorts of downsides (less trust of police, civil rights violations, etc.). Sounds like lousy policy to me, but that may be why I am not an elected official.
